Methyl tertiary-butyl ether (MTBE) was originally licensed as a motor fuel additive replacing lead as lead is known to accumulate in the environment and affect human health. The increase use of MTBE lead to its increased release to the surface and ground waters in a number of ways; for example through leaking of petrol storage, from spills, emissions from marine engines, from air deposition etc. Further, MTBE is highly soluble in water, resist biodegradation, moves rapidly with groundwater and does not adsorb easily to soil particles. Thus, increase use and characteristics of MTBE lead to MTBE being considered a contaminant in water and soil. Various treatment methods for removing contaminants from water involve adsorption on activated carbon, stripping with air, sterilization by chlorination or ozonization. All of these methods however has some limitations for the removal of tough contaminants such as MTBE.
Photo-catalytic degradation of contaminants by the action of UV light is becoming more popular technique for water purification. The process include generation of a photo-catalyst or use of a known photo-catalyst to photo-catalyze the contaminants for its partial or complete degradation into simple substances such as water, carbon dioxide and possibly mineral acid. A number of issued patents and patent applications disclose different methods for the degradation of MTBE. U.S. Pat. No. 6,468,434 to Pappa et al., describes a method that involves TiO2, a well-known semiconductor metal oxide catalyst, a mineral acid (sulfuric acid) and UV light under pressurized oxygen atmosphere to degrade MTBE.; U.S. Pat. No. 7,341,863 to Vandenbergh describes a method of degradation of MTBE and tertiary-butyl alcohol (TBA) using a mixture bacteria (Pseudomonas putida) in contaminated water and/or soil; U.S. Pat. No. 6,197,206 to Wasinger describes a method for removing MTBE from contaminated water by using an oxidizing gas such as ozone or ozone enriched fluid and then stripping the oxidized products. Further studies by Eslami et al (1) also reported a ZnO/H2O2 system for photocatalytic degradation of MTBE in presence of UV light.
However, there is still a lack of a simple and a cost-effective method of a photo-catalytic degradation of contamination in water and soil.